Integrally bladed rotors (IBR), also known as blisks, comprises a circumferential row of blades integrally formed in the periphery of a hub. The blades in the row are typically machined such as to have the same airfoil shape. However, it has been found that the uniformity between the blades increases flutter susceptibility. Flutter may occur when two or more adjacent blades in a blade row vibrate at a frequency close to their natural vibration frequency and the vibration motion between the adjacent blades is substantially in phase.
One solution proposed in the past to avoid flutter instability is to mistune the IBR by cropping the leading edge tip of some of the blades around the hub. However, this solution is not fully satisfactory from an aerodynamic and a manufacturing point of view.
Accordingly, there is a need to provide a new frequency mistuning method suited for integrally bladed rotors.